Journal
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
Volume 51, Issue 4, Pages 924-935Publisher
WILEY-BLACKWELL
DOI: 10.1002/pola.26453
Keywords
atom transfer radical polymerization; comb-like polymers; liquid-crystalline polymers; phase behaviors; the degrees of crystallinity
Categories
Funding
- Innovation Platform Open Foundation of University of Hunan Province [10k067]
- National Nature Science Foundation of China [51073131, 21174117, 21104062]
Ask authors/readers for more resources
A series of comb-like polymers, poly{2,5-bis[(4-octadecyloxyphenyl) oxycarbonyl]-styrenes} (P-OC18s) with different molecular weights (M-n) and low molecular weight distributions have been successfully synthesized via atom transfer radical polymerization. The phase behaviors have been investigated by a combination of techniques including differential scanning calorimetry, polarized optical microscopy, wide-angle X-ray diffraction, and temperature-variable FTIR spectroscopy. One hand, phase behaviors of the alkyl tails were strongly influenced by the mesogens of polymers, leading to the poor packing of the alkyl tails and the low melting. The other hand, the liquid crystalline phase structures of polymers were found to be strongly M-n dependent. The samples with M-n <= 4.6 x 10(4) formed a smectic phase in low temperature and an isotropic phase in high temperature. The samples with M-n >= 5.2 x 10(4) displayed a reentrant isotropic phase, which was separating the smectic phase and columnar nematic phase. Meantime, the experiment results showed that the glass temperature and the transition temperature from smectic phase to isotropic phase both slightly increased with the increase of MnS; however, the transition temperature from isotropic phase to columnar phase sharply decreased with the MnS improved. The reappearance of isotropic phase is due to the competing between the driving force of the enthalpy and the driving force of the entropy. (C) 2012 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 924-935
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available